Difference between revisions of "Unicode Free Operator"

Latest revision as of 17:20, 27 May 2010

This page describes Unicode (5.0) free operator to be implemented in ISE compiler. We hightlight the relationship between special characters mentioned in Unicode standard and printable characters specified in the ECMA standard.

Legend

<accepted> marks characters that are allowed as part of a free operator. 
<denied> marks characters that are not allowed as part of a free operator. 
<undecided> marks characters that are not yet decided. 

Space Characters

<denied>

Code
Position Name
0020 SPACE
00A0 NO-BREAK SPACE
2000 EN QUAD
2001 EM QUAD
2002 EN SPACE
2003 EM SPACE
2004 THREE-PER-EM SPACE
2005 FOUR-PER-EM SPACE
2006 SIX-PER-EM SPACE
2007 FIGURE SPACE
2008 PUNCTUATION SPACE
2009 THIN SPACE
200A HAIR SPACE
3000 IDEOGRAPHIC SPACE

Currency symbols

<accepted> Unicode standard emphasizes that currency symbols in ISO/IEC 10646 do not necessarily identify the currency of a country.

Alternate format characters

General format characters

Zero-width boundary indicators

COMBINING GRAPHEME JOINER (034F) -- Used to indicate that adjacent characters belong to the same grapheme cluster.
SOFT HYPHEN (00AD) -- a format character that indicates a preferred intra-word linebreak opportunity
ZERO WIDTH SPACE (200B) -- This character behaves like a SPACE in that it indicates a word boundary, but unlike SPACE it has no presentational width.
WORD JOINER (2060) and ZERO WIDTH NO-BREAK SPACE (FEFF) -- These characters behave like a NOBREAK SPACE in that they indicate the absence of word boundaries, but unlike NO-BREAK SPACE they have no presentational width.
ZERO WIDTH NON-JOINER (200C) -- This character indicates that the adjacent characters are not joined together in cursive connection even when they would normally join together as cursive letter forms.
ZERO WIDTH JOINER (200D) -- This character indicates that the adjacent characters are represented with joining forms in cursive connection even when they would not normally join together as cursive letter forms.

Format separators

LINE SEPARATOR (2028)
PARAGRAPH SEPARATOR (2029)

Bidirectional text formatting

LEFT-TO-RIGHT MARK (200E) -- In bidirectional formatting, this character acts like a left-to-right character (such as LATIN SMALL LETTER A).
RIGHT-TO-LEFT MARK (200F) -- In bidirectional formatting, this character acts like a right-to-left character (such as ARABIC LETTER NOON).
LEFT-TO-RIGHT EMBEDDING (202A) -- This character is used to indicate the start of a left-to-right implicit embedding.
RIGHT-TO-LEFT EMBEDDING (202B) -- This character is used to indicate the start of a right-to-left implicit embedding.
LEFT-TO-RIGHT OVERRIDE (202D) -- This character is used to indicate the start of a left-to-right explicit embedding.
RIGHT-TO-LEFT OVERRIDE (202E) -- This character is used to indicate the start of a right-to-left explicit embedding.
POP DIRECTIONAL FORMATTING (202C) -- This character is used to indicate the termination of an implicit or explicit directional embedding initiated by the above characters.

Other boundary indicators

NARROW NO-BREAK SPACE (202F) -- This character is a non-breaking space. It is similar to 00A0 NO-BREAK SPACE, except that it is rendered with a narrower width.

Script-specific format characters

Hangul fill characters

HANGUL FILLER (3164) -- This character represents the fill value used with the standard spacing Jamos.
HALFWIDTH HANGUL FILLER (FFA0) -- As with the other halfwidth characters, this character is included for compatibility with certain systems that provide halfwidth forms of characters.

Symmetric swapping format characters

INHIBIT SYMMETRIC SWAPPING (206A) -- Between this character and the following ACTIVATE SYMMETRIC SWAPPING format character (if any), the stored characters listed in clause 19 are interpreted and rendered as LEFT and RIGHT, and the processing specified in that clause is not performed.
ACTIVATE SYMMETRIC SWAPPING (206B) -- Between this character and the following INHIBIT SYMMETRIC SWAPPING format character (if any), the stored characters listed in clause 19 are interpreted and rendered as OPENING and CLOSING characters as specified in that clause.

Character shaping selectors

INHIBIT ARABIC FORM SHAPING (206C) Between this character and the following ACTIVATE ARABIC FORM SHAPING format character (if any), the character shaping determination process is inhibited. The stored Arabic presentation forms are presented without shape modification. This is the default state.
ACTIVATE ARABIC FORM SHAPING (206D) Between this character and the following INHIBIT ARABIC FORM SHAPING format character (if any), the stored Arabic presentation forms are presented with shape modification by means of the character shaping determination process.

Numeric shape selectors

NATIONAL DIGIT SHAPES (206E) -- Between this character and the following NOMINAL DIGIT SHAPES format character (if any), digits from 0030 to 0039 are rendered with the appropriate national digit shapes as specified by means of appropriate agreements.
NOMINAL DIGIT SHAPES (206F) -- Between this character and the following NATIONAL DIGIT SHAPES format character (if any), the digits from 0030 to 0039 are rendered with the shapes as those shown in the code tables for those digits. This is the default state.

Mongolian vowel separator

MONGOLIAN VOWEL SEPARATOR (180E) -- It indicates a special form of the graphic symbol for the letter A or E and the preceding consonant.

Ideographic description characters

An Ideographic Description Character (IDC) is a graphic character, which is used with a sequence of other graphic characters to form an Ideographic Description Sequence (IDS). IDS is not a character and therefore is not a member of the repertoire of ISO/IEC 10646.

IDEOGRAPHIC DESCRIPTION CHARACTER LEFT TO RIGHT (2FF0)
IDEOGRAPHIC DESCRIPTION CHARACTER ABOVE TO BELOW (2FF1)
IDEOGRAPHIC DESCRIPTION CHARACTER LEFT TO MIDDLE AND RIGHT (2FF2)
IDEOGRAPHIC DESCRIPTION CHARACTER ABOVE TO MIDDLE AND BELOW (2FF3)
IDEOGRAPHIC DESCRIPTION CHARACTER FULL SURROUND (2FF4)
IDEOGRAPHIC DESCRIPTION CHARACTER SURROUND FROM ABOVE (2FF5)
IDEOGRAPHIC DESCRIPTION CHARACTER SURROUND FROM BELOW (2FF6)
IDEOGRAPHIC DESCRIPTION CHARACTER SURROUND FROM LEFT (2FF7)
IDEOGRAPHIC DESCRIPTION CHARACTER SURROUND FROM UPPER LEFT (2FF8)
IDEOGRAPHIC DESCRIPTION CHARACTER SURROUND FROM UPPER RIGHT (2FF9)
IDEOGRAPHIC DESCRIPTION CHARACTER SURROUND FROM LOWER LEFT (2FFA)
IDEOGRAPHIC DESCRIPTION CHARACTER OVERLAID (2FFB)

Interlinear annotation characters

If the interlinear annotation characters are filtered out during processing, then all characters between the Interlinear Annotation Separator and the Interlinear Annotation Terminator should also be filtered out.

INTERLINEAR ANNOTATION ANCHOR (FFF9)
INTERLINEAR ANNOTATION SEPARATOR (FFFA)
INTERLINEAR ANNOTATION TERMINATOR (FFFB)

Subtending format characters

0600 ARABIC NUMBER SIGN
0601 ARABIC SIGN SANAH
0602 ARABIC FOOTNOTE MARKER
06DD ARABIC END OF AYAH
070F SYRIAC ABBREVIATION MARK

Variation selectors

Variation selectors are combining characters following immediately a specific base character to indicate a specific variant form of graphic symbol for that character.

FE00 VARIATION SELECTOR-1
FE01 VARIATION SELECTOR-2
FE02 VARIATION SELECTOR-3
FE03 VARIATION SELECTOR-4
FE04 VARIATION SELECTOR-5
FE05 VARIATION SELECTOR-6
FE06 VARIATION SELECTOR-7
FE07 VARIATION SELECTOR-8
FE08 VARIATION SELECTOR-9
FE09 VARIATION SELECTOR-10
FE0A VARIATION SELECTOR-11
FE0B VARIATION SELECTOR-12
FE0C VARIATION SELECTOR-13
FE0D VARIATION SELECTOR-14
FE0E VARIATION SELECTOR-15
FE0F VARIATION SELECTOR-16

Format characters for musical symbols

1D159 MUSICAL SYMBOL NULL NOTEHEAD
1D173 MUSICAL SYMBOL BEGIN BEAM
1D174 MUSICAL SYMBOL END BEAM
1D175 MUSICAL SYMBOL BEGIN TIE
1D176 MUSICAL SYMBOL END TIE
1D177 MUSICAL SYMBOL BEGIN SLUR
1D178 MUSICAL SYMBOL END SLUR
1D179 MUSICAL SYMBOL BEGIN PHRASE
1D17A MUSICAL SYMBOL END PHRASE

Tag characters

E0000–E007F